Extract emails into separate package with clean interface

- Create packages/emails/ with EmailClient interface abstraction
- Wrap Postmark ServerClient in adapter for clean typing
- Add createLoggingEmailClient for dev mode (logs to console)
- Split email templates into individual files with full test coverage
- Update api-server to use new package via context injection
- Remove EMAIL_DEV_MODE - now uses POSTMARK_API_KEY presence
- Delete apps/api-server/src/utils/email.ts

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api-server/src/procedures/orgs/invites.ts

@@ -3,12 +3,12 @@
  */
 
 import { ORPCError } from "@orpc/server";
+import { sendOrgInviteEmail } from "@reviq/emails";
 import { ORG_INVITE_EXPIRY_DAYS } from "../../constants.js";
 import {
   generateExpiry,
   generateSecureBase58Token,
 } from "../../utils/crypto.js";
-import { sendOrgInviteEmail } from "../../utils/email.js";
 import { authMiddleware, os } from "../base.js";
 import { getMembership, lookupOrgBySlug, requireRole } from "./helpers.js";
 
@@ -122,7 +122,17 @@ export const invitesCreate = os.orgs.invites.create
 
     // Send invitation email
     const inviterName = context.user.displayName ?? context.user.email;
-    await sendOrgInviteEmail(email, token, org.displayName, inviterName, role);
+    await sendOrgInviteEmail({
+      client: context.email.client,
+      fromAddress: context.email.fromAddress,
+      baseUrl: context.email.baseUrl,
+      email,
+      token,
+      orgName: org.displayName,
+      inviterName,
+      role,
+      expiryDays: ORG_INVITE_EXPIRY_DAYS,
+    });
 
     return { success: true };
   });